U.S. patent number 10,494,015 [Application Number 15/712,765] was granted by the patent office on 2019-12-03 for steer axle with integrated directional control.
This patent grant is currently assigned to Dana Heavy Vehicle Systems Group, LLC. The grantee listed for this patent is Dana Heavy Vehicle Systems Group, LLC. Invention is credited to Mark A. Davis, Stoyan I. Stoychev.
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United States Patent |
10,494,015 |
Davis , et al. |
December 3, 2019 |
Steer axle with integrated directional control
Abstract
A steer-by-wire steering system having an I-beam and a steering
gear housing coupled therewith. An input shaft assembly may be at
least partially disposed within the steering gear housing. A
steering knuckle having a kingpin boss and an output shaft having a
first end at least partially disposed within the kingpin boss. A
second end of the output shaft at least partially disposed within
the steering gear housing.
Inventors: |
Davis; Mark A. (Kalamazoo,
MI), Stoychev; Stoyan I. (Sylvania, OH) |
Applicant: |
Name |
City |
State |
Country |
Type |
Dana Heavy Vehicle Systems Group, LLC |
Maumee |
OH |
US |
|
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Assignee: |
Dana Heavy Vehicle Systems Group,
LLC (Maumee, OH)
|
Family
ID: |
59955486 |
Appl.
No.: |
15/712,765 |
Filed: |
September 22, 2017 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20180086376 A1 |
Mar 29, 2018 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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62398928 |
Sep 23, 2016 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B62D
5/0418 (20130101); B62D 7/18 (20130101); B62D
5/001 (20130101) |
Current International
Class: |
B62D
5/04 (20060101); B62D 5/00 (20060101); B62D
7/18 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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1757469 |
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Feb 2007 |
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EP |
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2610133 |
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Jul 2013 |
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EP |
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2935672 |
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Mar 2010 |
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FR |
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2012032987 |
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Mar 2012 |
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WO |
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WO-2014101756 |
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Jul 2014 |
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WO |
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Other References
European Patent Office, Extended European Search Report with
Written Opinion issued in Application EP17192735.3, dated Feb. 9,
2018, 14 pages, European Patent Office, Hague Netherlands. cited by
applicant.
|
Primary Examiner: Hurley; Kevin
Attorney, Agent or Firm: Marshall & Melhorn, LLC
Claims
What is claimed is:
1. A steer-by-wire steering system for a vehicle, comprising: a
beam axle; a steering gear housing coupled with a first end of said
beam axle; an input shaft assembly at least partially disposed
within said steering gear housing; a steering knuckle having a
kingpin boss; and an output shaft laterally spaced from said beam
axle traverse to a longitudinal axis of said vehicle, wherein said
output shaft includes a first end disposed within said kingpin boss
and a second end disposed within and terminating in said steering
gear housing.
2. The steer-by-wire steering system for said vehicle according to
claim 1, further comprising: a steering input in electronic
communication with a controller.
3. The steer-by-wire steering system for said vehicle according to
claim 1, wherein said second end of said output shaft is drivingly
engaged with said input shaft assembly.
4. A steer-by-wire steering system, comprising: a knuckle having a
kingpin boss; a steering gear housing coupled with said knuckle; an
input shaft assembly at least partially disposed within said
steering gear housing; an output shaft having a first end and an
opposite second end, wherein said first end is disposed within said
kingpin boss of said knuckle; and a beam axle, wherein said second
end of said output shaft is coupled to said beam axle such that
there is no rotation therebetween.
5. The steer-by-wire steering system according to claim 4, further
comprising: a steering input in electronic communication with a
controller.
6. The steer-by-wire steering system according to claim 4, wherein
said second end of said output shaft is drivingly engaged with said
input shaft assembly for rotation thereby.
7. The steer-by-wire steering system according to claim 4, wherein
said input shaft assembly is disposed transverse to a longitudinal
axis of said beam axle at a zero turn angle.
8. The steer-by-wire steering system according to claim 4, wherein
said input shaft assembly is disposed parallel to a longitudinal
axis of said beam axle at a zero turn angle.
9. The steer-by-wire steering system according to claim 4, further
comprising: a beam axle head coupled with said beam axle, wherein
said second end of said output shaft is at least partially disposed
within said beam axle head.
10. The steer-by-wire steering system according to claim 4, wherein
said steering gear housing is at least partially disposed through
an ear of said knuckle.
Description
BACKGROUND
The present disclosure relates to a vehicle steering system;
particularly to a steer axle with integrated directional control.
In a conventional steering system directional control is obtained
through steering gears mounted remotely on a vehicle frame. The
steering gears control vehicle direction by providing a desired
wheel turn angle through a series of mechanical and/or hydraulic
linkages on a steer axle. Conventional steering systems may include
a steering column mechanically connected to the steering gear; the
steering gear may operate a pitman arm connected to a drag link
transverse to an axle beam; and the drag link may be connected to a
steering arm connected to a first steering knuckle on which a wheel
is mounted. Conventional steering systems may also include a tie
rod connecting the first steering knuckle with a second steering
knuckle. Hydraulic and/or electric actuators may also be included
in a conventional steering system.
Conventional steering systems are disadvantaged by their
complexity, weight, and Ackerman steering geometry error. The
presently disclosed subject matter describes a steering system that
simplifies the steer axle control system, reduces system complexity
and weight, reduces assembly time, and in at least one embodiment,
eliminates Ackerman steering geometry error. The presently
disclosed subject matter also provides a platform for integrating
autonomous vehicle driving controls.
SUMMARY
The present disclosure provides for a steer-by-wire steering
system. In one embodiment, the steer-by-wire steering system
includes an I-beam having a steering gear housing coupled
therewith. An input shaft assembly may be at least partially
disposed within the steering gear housing. Further, the
steer-by-wire system may include a steering knuckle having a
kingpin boss. An output shaft may have a first end at least
partially disposed within the kingpin boss, and a second end at
least partially disposed within the steering gear housing.
In another embodiment, there steer-by-wire system may include a
steering gear housing coupled with a knuckle. An input shaft
assembly may be at least partially disposed within the steering
gear housing. An output shaft may have a first end at least
partially disposed within the steering gear housing, and a second
end coupled with an I-beam.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
The accompanying drawings are incorporated herein as part of the
specification. The drawings described herein illustrate embodiments
of the presently disclosed subject matter, and are illustrative of
selected principles and teachings of the present disclosure.
However, the drawings do not illustrate all possible
implementations of the presently disclosed subject matter, and are
not intended to limit the scope of the present disclosure in any
way.
FIG. 1 schematically depicts a vehicle steering system according to
an embodiment of the presently disclosed subject matter;
FIG. 2 illustrates a portion of the vehicle steering system
according to FIG. 1;
FIG. 3 illustrates a portion of a vehicle steering system according
to another embodiment of the presently disclosed subject
matter;
FIG. 4 illustrates a side-elevation of a portion of the vehicle
steering system according to FIG. 3;
FIG. 5 illustrates a portion of a vehicle steering system according
to another embodiment of the presently disclosed subject
matter;
FIG. 6 illustrates a side-elevation of a portion of the vehicle
steering system according to FIG. 5;
FIG. 7 illustrates a knuckle according to an embodiment of the
presently disclosed subject matter;
FIG. 8 illustrates a cross-section of the knuckle according to FIG.
7;
FIG. 9 illustrates a cross-section of a knuckle according to
another embodiment of the presently disclosed subject matter;
and
FIG. 10 illustrates a knuckle according to still another embodiment
of the presently disclosed subject matter.
DETAILED DESCRIPTION OF EMBODIMENTS
It is to be understood that the invention may assume various
alternative orientations and step sequences, except where expressly
specified to the contrary. It is also to be understood that the
specific devices, assemblies, systems and processes illustrated in
the attached drawings, and described in the following specification
are simply exemplary embodiments of the inventive concepts defined
herein. Hence, specific dimensions, directions or other physical
characteristics relating to the embodiments disclosed are not to be
considered as limiting, unless expressly stated otherwise. Also,
although they may not be, like elements in various embodiments
described herein may be commonly referred to with like reference
numerals within this section of the application.
Certain embodiments of a steering system 100 are utilized with
heavy vehicles such as commercial trucks. However, the steering
system 100 may be utilized with, but is not limited to use with,
military vehicles, off-highway vehicles, passenger vehicles,
electric vehicles, and autonomous or semi-autonomous driving
vehicles.
As illustrated in FIG. 1, in an embodiment, the steering system 100
may be a steer-by-wire system. The steering system 100 may include
a steering input 102 by which a vehicle operator may enter a
desired wheel turn-angle into the steering system 100. The steering
input 102 may include, but is not limited to, an autonomous or
semi-autonomous sensory processing apparatus, a steering wheel, a
joystick, or a twin lever steering apparatus. The steering system
100 also includes a controller 104 electronically coupled with the
steering input 102. The controller 104 interfaces with and receives
an electrical signal from the steering input 102. The controller
104 processes the signal received from the steering input 102 and
outputs a signal to a first directional control assembly 106, 206,
306 electronically coupled with the controller 104. The controller
104 may also provide road feedback to the vehicle operator by
transmitting a signal to the steering input 102. In an embodiment
where the steering input 102 is a steering wheel, the controller
104 may provide road feedback to the vehicle operator by applying
torque to the steering wheel.
As illustrated in FIG. 2, in an embodiment, the first directional
control assembly 106 comprises a steering gear housing 110. The
steering gear housing 110 may be coupled with a first end 108A of
an I-beam 108 via a plurality of fasteners 112. The I-beam may also
be referred to as a beam axle or solid axle. In another embodiment,
the steering gear housing 110 may be welded to the I-beam first end
108A. In yet another embodiment, the steering gear housing 110 may
be formed integral and unitary with the I-beam first end 108A. The
first directional control assembly 106 may include an input shaft
assembly 132 disposed inside the steering gear housing 110. In an
embodiment, the input shaft assembly 132 is coupled with an
electric motor (not depicted). The electric motor controls the
input shaft assembly 132. The electric motor is electronically
coupled with the controller 104, such that the electric motor may
respond to signals from the steering input 102. The electric motor
may receive a signal from the controller 104 which determines the
turn angle output by the first directional control assembly 106.
The electric motor may be coupled with a first end of the input
shaft assembly 132. In another embodiment, the input shaft assembly
132 may be controlled by a hydraulic system (not depicted).
In other embodiments, the first directional control assembly 106
input assembly may include, but is not limited to, a worm gear
assembly, a hydraulic assisted gear assembly, or an electronic
assisted gear assembly.
The electric motor controls a series of mechanical and/or hydraulic
system linkages within the steering gear housing 110 which are
coupled with the output shaft 114. The output shaft 114 may replace
a kingpin in a conventional steering system. The output shaft 114
is coupled with a knuckle 116 such that the output shaft 114 and
the knuckle 116 may pivot together in response to input from the
electric motor. In an embodiment, the knuckle 116 includes a
kingpin boss 118. The output shaft 114 is at least partially
disposed in the kingpin boss 118 and an aperture 119 through the
housing 110. The first directional control assembly 106 further
acts as an I-beam head, of the I-beam 108, in the kingpin
joint.
In the embodiment illustrated in FIG. 2, a second directional
control assembly 107 may be disposed at a second end 1086 of the
I-beam 108. The second directional control assembly 107, similar to
the first directional control assembly 106, may include an input
shaft assembly (not depicted) coupled with a second electric motor
(not depicted). The second electric motor may be coupled with a
first end of the input shaft assembly. The second electric motor is
electronically coupled with the controller 104, such that the
second electric motor may respond to signals from the steering
input 102. The second electric motor drives a series of mechanical
and/or hydraulic linkages drivingly coupled with an output shaft
(not depicted). The output shaft is coupled with a knuckle (not
depicted) such that the output shaft and the knuckle may pivot
together in response to input from the second electric motor.
In the embodiment illustrated in FIGS. 1 and 2, where the first and
second directional control assemblies 106, 107 are integrated on
either side of the I-beam 108, the necessity of a tie-rod assembly
and the associated ball joints (not depicted) is obviated.
Utilizing independent first and second directional control
assemblies 106, 107 also eliminates the Ackerman steering error by
allowing direct independent control of each wheel turn angle.
In another embodiment, as illustrated in FIGS. 3 and 4, directional
control assemblies 206, 207 may be integrated into the respective
steering knuckle. The first directional control assembly 206 may
comprise a steering gear housing 210. The steering gear housing 210
may be formed unitary with a knuckle 216. In another embodiment,
the steering gear housing 210 may be coupled with the knuckle 216.
The knuckle 216 includes a kingpin boss 218. A first end of an
output shaft 214 may be disposed in and rotatably coupled with the
kingpin boss 218. A second end of the output shaft 214 may be
disposed in an I-beam head 230.
The first directional control assembly 206 may include an input
shaft assembly 232 disposed inside the steering gear housing 210.
The input shaft assembly 232 is coupled with an electric motor (not
depicted). The input shaft assembly 232 may comprise, but is not
limited to, a worm gear assembly, a hydraulic assisted gear
assembly, or an electronic assisted gear assembly. The electric
motor controls a series of mechanical and/or hydraulic linkages
within the housing 210 which are coupled with the output shaft 214.
The output shaft 214 may replace a kingpin in a conventional
steering system. The output shaft 214 is rotatably coupled with the
knuckle 216 such that the knuckle 216 may pivot around the output
shaft 214 in response to input from the electric motor. The output
shaft 214 is coupled with the I-beam head 230 so that there is no
rotation therebetween. Further, the output shaft 214 transmits
torque to the I-beam head 232. Utilizing the output shaft 214 as a
kingpin eliminates the need for separate bushings/bearings
between.
The output shaft 214 may comprise a plurality of gear teeth (not
depicted) on the outer surface thereof. In another embodiment, the
output shaft 214 may be coupled with a gear (not depicted) such as
a sector gear. The output shaft 214 may be in meshed engagement
with the input shaft assembly 232.
In another embodiment, as illustrated in FIGS. 5 and 6, a
directional control assembly 306 may be integrated into a steering
knuckle 316. The directional control assembly 306 is similar to the
first directional control assembly 206. However, where the first
directional control assembly steering gear housing 210 and input
assembly is oriented transverse to their respective wheel assembly
spindle (not depicted), a steering gear housing 310 of a
directional control assembly 306 and input assembly (not depicted)
are oriented parallel with a spindle 340. In other, words, the
steering gear housing 310 is oriented parallel with a longitudinal
axis of an I-beam at a zero turn angle. In another embodiment, not
depicted, the steering gear housing may be oriented at any angle
with respect to said I-beam at a zero turn angle.
The steering gear housing 310 may share a first wall portion (not
depicted) with a kingpin boss 318 and a second wall portion (not
depicted) with an ear 317 of a steering knuckle 316. Because the
steering gear housing 310 may comprise a first and second wall
portion shared with the steering knuckle 316, the directional
control assembly 306 may comprise a lighter weight and/or more
compact alternative to the first directional control assembly
206.
A first end of an output shaft 314 may be disposed in and rotatably
coupled with the kingpin boss 318. A second end of the output shaft
314 may be disposed in an I-beam head 330. The first directional
control assembly 306 may include an input shaft assembly (not
depicted) disposed inside the steering gear steering gear housing
310. The input shaft assembly is coupled with an electric motor
(not depicted). The input shaft assembly may comprise, but is not
limited to, a worm gear assembly, a hydraulic assisted gear
assembly, or an electronic assisted gear assembly. The electric
motor controls a series of mechanical and/or hydraulic linkages
within the steering gear housing 310 which are coupled with the
output shaft 314. The output shaft 314 may replace a kingpin in a
conventional steering system. The output shaft 314 is rotatably
coupled with the knuckle 316 such that the knuckle 316 may pivot
around the output shaft 314 in response to input from the electric
motor. The output shaft 314 is coupled with the I-beam head 330 so
that there is no rotation therebetween.
In yet another embodiment (not depicted), a first directional
control assembly coupled with a first steering knuckle or an
I-beam, as described supra, may be utilized in conjunction with a
tie-rod assembly coupled with a second steering knuckle. In this
embodiment, only one directional control assembly is necessary to
output a turn angle at two wheel assemblies.
Conventionally, steering knuckles are produced through a forging
method. In embodiments where a directional control assembly housing
and input assembly are integrated into a steering knuckle as
disclosed supra, it may be necessary or beneficial to produce the
steering knuckles through a casting process. The casting method may
require, or benefit, from increasing the dimensions of the steering
knuckle. However, steering knuckle spindles are defined by industry
standards.
Therefore, in an embodiment, as illustrated in FIGS. 7 and 8, a
cast steering knuckle 416 may comprise a cast knuckle body 442 and
a separately manufactured spindle 440 coupled therewith. The
knuckle body 442 may comprise knuckle ears 444, 446 and a kingpin
boss 418. The knuckle boss 418 may comprise a flange 448 having a
surface 450 where an input assembly and housing (not depicted) may
be coupled. The kingpin boss 418 further comprises an aperture 452
disposed through the flange surface 450. The knuckle body 442 also
comprises a recess 454 and an opening 458 coaxial with the aperture
452. The recess 454 comprises a diameter larger than the diameter
of the opening 458 creating a shoulder 455 where the recess 454 and
the opening 458 meet.
The spindle 440 may comprise a tapered shaft having a smaller
diameter at an outboard end 441 and a larger diameter at an inboard
end 443. The inboard end 443 of the spindle 440 may include a
flange 456. In addition, the spindle 440 may comprise a fluid
conduit 460 extending from the inboard end 443 to the outboard end
441. In assembling the steering knuckle 416, the spindle 440 may be
inserted through the aperture 452, the recess 454, and the opening
458. The spindle 440 may then be press fit into recess 454 and the
opening 458 until the flange 456 abuts the shoulder 455.
In another embodiment, as illustrated in FIG. 9, a cast steering
knuckle 516 may comprise a knuckle body 542 and a separately
manufactured spindle 540 coupled therewith. As described in U.S.
Pat. No. 6,916,030, the knuckle body 542 may be insert-cast about
the spindle 540. The spindle 540 may include multiple flanges 556
and/or projections 557 whereby a mechanical interlock is achieved
between the cast knuckle body 542 and the spindle 540. The
disclosure of U.S. Pat. No. 6,916,030 is incorporated herein by
reference in its entirety.
In yet another embodiment, a steering knuckle may comprise an
as-cast unitary component comprising austempered ductile iron, also
known as ADI. In still another embodiment, a steering knuckle may
comprise an as-cast unitary component wherein the spindle diameter
has been increased to match the drive axle standard for spindle
diameter.
In another embodiment, as illustrated in FIG. 10, a cast steering
knuckle 616 may comprise a knuckle body 642 and a separately
manufactured spindle 640 coupled therewith. The spindle may
comprise a bolt flange 656 by which the spindle 640 may be
mechanically fastened to, or coupled with, the knuckle body 642 via
a plurality of mechanical fasteners 660.
While various embodiments of the presently disclosed subject matter
have been described above, it should be understood that they have
been presented by way of example, and not limitation. It will be
apparent to persons skilled in the relevant arts that the disclosed
subject matter may be embodied in other specific forms without
departing from the spirit or essential characteristics thereof. The
embodiments described above are therefore to be considered in all
respects as illustrative, not restrictive.
* * * * *